<template>
	<div style="padding: 10px; margin-bottom: 50px">
		<el-row>
			<el-col :span="4">
				<el-card style="width: 300px; height: 300px; color: #333">
					<div style="padding-bottom: 10px; border-bottom: 1px solid #ccc">在线用户<span style="font-size: 12px">（点击聊天气泡开始聊天）</span></div>
					<div style="padding: 10px 0" v-for="user in users" :key="user.username">
						<span @click="chatUser = user.username">{{ user.username }}</span>
						<span style="font-size: 12px; color: limegreen; margin-left: 5px" v-if="user.username === chatUser">chatting...</span>
					</div>
				</el-card>
			</el-col>

			<el-col :span="20">
				<div style="width: 800px; margin: 0 auto; background-color: white; border-radius: 5px; box-shadow: 0 0 10px #ccc">
					<div style="text-align: center; line-height: 50px">Web聊天室（{{ chatUser }}）</div>
					<div style="height: 350px; overflow: auto; border-top: 1px solid #ccc" v-html="content"></div>
					<div style="height: 200px">
						<textarea
							v-model="text"
							style="
								height: 160px;
								width: 100%;
								padding: 20px;
								border: none;
								border-top: 1px solid #ccc;
								border-bottom: 1px solid #ccc;
								outline: none;
							"
						></textarea>
						<div style="text-align: right; padding-right: 10px">
							<el-button type="primary" size="mini" @click="send">发送</el-button>
						</div>
					</div>
				</div>
			</el-col>
		</el-row>
	</div>
</template>

<script>
import api from "/@/api.js";
let socket;

export default {
	name: 'Im',
	data() {
		return {
			circleUrl: 'https://img0.baidu.com/it/u=3845858759,1009922837&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=500',
			user: {},
			isCollapse: false,
			users: [],
			chatUser: '',
			text: '',
			messages: [],
			content: '',
		};
	},
	created() {
		this.init();
	},
	methods: {
		send() {

			/*if (!this.chatUser) {
				this.$message({ type: 'warning', message: '请选择聊天对象' });
				return;
			}*/


			if (!this.text) {
				this.$message({ type: 'warning', message: '请输入内容' });
			} else {
				if (typeof WebSocket == 'undefined') {
					console.log('您的浏览器不支持WebSocket');
				} else {
					console.log('您的浏览器支持WebSocket');
					// 组装待发送的消息 json
					// {"from": "zhang", "to": "admin", "text": "聊天文本"}
					
					
					//let message = { from: this.user.username, to: this.chatUser, text: this.text };
					let message = { from: this.user.username, to: 'export', text: this.text };


					socket.send(JSON.stringify(message)); // 将组装好的json发送给服务端，由服务端进行转发
					this.messages.push({ user: this.user.username, text: this.text });
					// 构建消息内容，本人消息
					this.createContent(null, this.user, this.text);
					this.text = '';
				}
			}
		},
		createContent(remoteUser, nowUser, text) {
			// 这个方法是用来将 json的聊天消息数据转换成 html的。
			let html;
			// 当前用户消息
			if (nowUser) {
				// nowUser 表示是否显示当前用户发送的聊天消息，绿色气泡
				html =
					'<div class="el-row" style="padding: 5px 0">\n' +
					'  <div class="el-col el-col-22" style="text-align: right; padding-right: 10px">\n' +
					'    <div class="tip left">' +
					text +
					'</div>\n' +
					'  </div>\n' +
					'  <div class="el-col el-col-2">\n' +
					'  <span class="el-avatar el-avatar--circle" style="height: 40px; width: 40px; line-height: 40px;">\n' +
					'    <img src="https://cube.elemecdn.com/3/7c/3ea6beec64369c2642b92c6726f1epng.png" style="object-fit: cover;">\n' +
					'  </span>\n' +
					'  </div>\n' +
					'</div>';
			} else if (remoteUser) {
				// remoteUser表示远程用户聊天消息，蓝色的气泡
				html =
					'<div class="el-row" style="padding: 5px 0">\n' +
					'  <div class="el-col el-col-2" style="text-align: right">\n' +
					'  <span class="el-avatar el-avatar--circle" style="height: 40px; width: 40px; line-height: 40px;">\n' +
					'    <img src="https://cube.elemecdn.com/3/7c/3ea6beec64369c2642b92c6726f1epng.png" style="object-fit: cover;">\n' +
					'  </span>\n' +
					'  </div>\n' +
					'  <div class="el-col el-col-22" style="text-align: left; padding-left: 10px">\n' +
					'    <div class="tip right">' +
					text +
					'</div>\n' +
					'  </div>\n' +
					'</div>';
			}
			console.log(html);
			this.content += html;
		},
		init() {
			this.user = sessionStorage.getItem('user') ? JSON.parse(sessionStorage.getItem('user')) : {};
			let username = this.user.account;

			let _this = this;
			if (typeof WebSocket == 'undefined') {
				console.log('您的浏览器不支持WebSocket');
			} else {
				console.log('您的浏览器支持WebSocket');
				let socketUrl = 'ws://'+ api.commonUrl.replace("http://","") +'/imserver/' + username + '-user';
				if (socket != null) {
					socket.close();
					socket = null;
				}
				// 开启一个websocket服务
				socket = new WebSocket(socketUrl);
				//打开事件
				socket.onopen = function () {
					console.log('websocket已打开');
				};
				//  浏览器端收消息，获得从服务端发送过来的文本消息
				socket.onmessage = function (msg) {
					console.log('收到数据====' + msg.data);
					let data = JSON.parse(msg.data); // 对收到的json数据进行解析， 类似这样的： {"users": [{"username": "zhang"},{ "username": "admin"}]}
					if (data.users) {
						// 获取在线人员信息
						_this.users = data.users.filter((user) => user.username !== username); // 获取当前连接的所有用户信息，并且排除自身，自己不会出现在自己的聊天列表里
					} else {
						// 如果服务器端发送过来的json数据 不包含 users 这个key，那么发送过来的就是聊天文本json数据
						//  // {"from": "zhang", "text": "hello"}
						
						/*if (data.from === _this.chatUser) {
							_this.messages.push(data);
							// 构建消息内容
							_this.createContent(data.from, null, data.text);
						}*/

						_this.messages.push(data);
						// 构建消息内容
						_this.createContent(data.from, null, data.text);
					}
				};
				//关闭事件
				socket.onclose = function () {
					console.log('websocket已关闭');
				};
				//发生了错误事件
				socket.onerror = function () {
					console.log('websocket发生了错误');
				};
			}
		},
	},
};
</script>

<style>
.tip {
	color: white;
	text-align: center;
	border-radius: 10px;
	font-family: sans-serif;
	padding: 10px;
	width: auto;
	display: inline-block !important;
	display: inline;
}

.right {
	background-color: deepskyblue;
}
.left {
	background-color: forestgreen;
}
</style>
